Abstract: Identifying fault system is the first step in seismic interpretation and a key component of formulating exploration and development strategies; it is of great significance for the early, middle, and late stages of exploration and development.Attribute extraction using seismic data with high resolution and high signal-to-noise ratio is the key to low-relief structure interpretation and fault detection.High-precision evaluation results of reservoir fault connectivity can effectively guide and formulate reasonable development technology plans, and improve oil and gas reservoir recovery efficiency.When oil and gas reservoirs are deeply buried and the underground geological conditions are complex, the quality of seismic data will be reduced.In this case, directly using methods based on seismic data discontinuity (e.g.coherence cube technology) to identify faults will lead to problems such as low resolution, imprecision, and insufficient description of faults connectivity; thus it is difficult to meet the needs of fine exploration.In order to improve the accuracy and resolution of fault prediction and analyze the connectivity of reservoir faults, we propose a method of reservoir fault prediction and connectivity evaluation, which combines fault enhancement based on a LoG operator, fault refinement based on feature vector, and fault connectivity assessment based on three-dimensional steady-state saturation and flow equation.As per a case study of Longmaxi shale reservoirs in Weiyuan, improved signal-to-noise ratio and horizontal and vertical resolution by fault enhancement and refinement facilitate detailed interpretation of small fractures; seismic attributes extracted after processing perform better than coherence attribute in fault identification with improved resolution and precision.Connected faults are highlighted using the connectivity evaluation method, and small faults are connected.According to above results and porosity prediction, fracture connectivity is divided into three types and evaluated separately.In conclusion, target reservoirs are rich in faults and medium- to small-scale fractures with good connectivity, which may function as the reservoir space and migration pathways of gas.